Aircraft Landing Gear Assembly Shimmy Damper

ABSTRACT

An aircraft vehicular assembly is provided that includes a nonelastomeric outer tubular member having an inner axial center bore with a tubular cylindrical frictional interface contiguous smooth inner surface segment, and a nonelastomeric inner member having an outer bonding surface segment. The nonelastomeric inner member is rotationally received in the outer member inner axial center bore with the nonelastomeric inner strut member rotatable within said outer member. An elastomer encompasses the nonelastomeric inner strut member outer bonding surface segment. The elastomer has an inner bonding surface segment and an outer grooved elastomer surface, the inner bonding surface segment is bonded to the nonelastomeric inner member outer bonding surface segment.

RELATED APPLICATIONS

This application continuation of U.S. patent application Ser. No.11/375,945 filed on Mar. 15, 2006 which is a Continuation-in-Part ofU.S. patent application Ser. No. 11/038,851 filed on Jan. 19, 2005 whichclaims the benefit of U.S. Provisional Patent Application No. 60/537,704filed on Jan. 20, 2004. All of the aforementioned applications areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to an aircraft landing gear and a methodof making an aircraft landing gear assembly. More particularly theinvention relates to aircraft landing gear with reduced oscillatingshimmy rotation vibrations and methods for making a landing gear with ashimmy damper for reducing oscillating rotations.

BACKGROUND OF THE INVENTION

There is a need for an effective and economical means for makingaircraft landing gear with improved performance and reliability. Thereis a need for economically feasible aircraft landing gear with a shimmydamper. There is a need for a robust system and method of making anaircraft landing gear shimmy damper for inhibiting oscillatingrotations.

SUMMARY

The invention includes an aircraft vehicular front wheel landing gearassembly. The landing gear assembly includes a nonelastomeric outerupper strut tubular member having an inner axial center bore with atubular cylindrical frictional interface inner surface segment. Thelanding gear assembly includes a nonelastomeric inner lower strut memberhaving an outer bonding surface segment. The nonelastomeric inner memberis rotationally received in the outer strut member inner axial centerbore with the nonelastomeric inner strut member rotatable within saidouter strut member. The landing gear assembly includes an elastomericsurface effect damper member encompassing the nonelastomeric inner strutmember outer bonding surface segment. The elastomeric surface effectdamper member has an inner bonding surface segment and an outerelastomer surface. The elastomeric surface effect damper inner bondingsurface segment is bonded to the nonelastomeric inner strut member outerbonding surface segment. The landing gear assembly includes a surfaceeffect lubricant disposed between the elastomeric surface effect damperouter elastomer surface and the nonelastomeric outer strut memberfrictional interface inner surface segment with the elastomeric surfaceeffect damper outer elastomer surface engaging the nonelastomeric outerstrut member frictional interface inner surface segment and inhibitingan oscillating shimmy rotation of the nonelastomeric inner lower strutmember.

The invention includes a method of making an aircraft vehicular frontwheel landing gear assembly. The method includes providing anonelastomeric outer upper strut tubular member having an inner axialcenter bore with a tubular cylindrical frictional interface innersurface segment. The method includes providing a nonelastomeric innerlower strut member rotationally receivable in the outer strut memberinner axial center bore with the nonelastomeric inner strut memberrotatable within said outer strut member. The nonelastomeric inner lowerstrut member has an outer bonding surface segment. The method includesbonding an elastomeric surface effect damper member to saidnonelastomeric inner strut member outer bonding surface segment, withsaid elastomeric surface effect damper member having an outer elastomersurface distal from said nonelastomeric inner strut member outer bondingsurface segment. The method includes rotationally receiving saidnonelastomeric inner strut rotationally receivable member in said outerstrut member inner axial center bore with said nonelastomeric innerstrut member rotatable within said outer strut member with saidelastomeric surface effect damper outer elastomer surface engaging saidnonelastomeric outer strut member frictional interface inner surfacesegment and inhibiting an oscillating shimmy rotation of saidnonelastomeric inner lower strut member.

The invention includes a method of making a shimmy damper for damping arotating oscillation. The method includes providing a nonelastomericouter upper tubular member having an inner axial center bore with atubular cylindrical frictional interface inner surface segment. Themethod includes providing a nonelastomeric inner lower memberrotationally receivable in said outer member inner axial center borewith said nonelastomeric inner member rotatable within said outermember. The nonelastomeric inner member has an outer bonding cylindricalsurface segment. The method includes bonding an elastomeric surfaceeffect damper member to said nonelastomeric inner member outer bondingcylindrical surface segment, with said elastomeric surface effect dampermember having an outer grooved elastomer surface distal from saidnonelastomeric inner member outer bonding cylindrical surface segment.The method includes rotationally receiving said nonelastomeric innermember in said outer member inner axial center bore with saidnonelastomeric inner member rotatable within said outer member with saidelastomeric surface effect damper outer grooved elastomer surfaceengaging said nonelastomeric outer member frictional interface innersurface segment and inhibiting an oscillating shimmy rotation of saidnonelastomeric inner member.

The invention includes a shimmy damper for damping a rotatingoscillation. The shimmy damper includes a nonelastomeric outer uppertubular member having an inner axial center bore with a tubularcylindrical frictional interface inner surface segment and anonelastomeric inner lower member having an outer bonding cylindricalsurface segment with the nonelastomeric inner member rotationallyreceived in the outer member inner axial center bore with thenonelastomeric inner member rotatable within said outer tubular member.The shimmy damper includes an elastomeric surface effect damper memberencompassing said nonelastomeric inner member outer bonding cylindricalsurface segment, said elastomeric surface effect damper member having aninner bonding cylindrical surface segment and an outer grooved elastomersurface, said elastomeric surface effect damper inner bondingcylindrical surface segment bonded to said nonelastomeric inner memberouter bonding cylindrical surface segment. The shimmy damper includes asurface effect lubricant, said surface effect lubricant disposed betweensaid elastomeric surface effect damper outer grooved elastomer surfaceand said nonelastomeric outer member frictional interface inner surfacesegment with said elastomeric surface effect damper outer groovedelastomer surface engaging said nonelastomeric outer member frictionalinterface inner surface segment and inhibiting an oscillating shimmyrotation of said nonelastomeric inner member.

The invention includes a method of making a rotating oscillation damperfor damping a rotating oscillation. The method includes providing anonelastomeric outer tubular member having an inner axial center borewith a tubular cylindrical frictional interface inner surface segment.The method includes providing a nonelastomeric inner member rotationallyreceivable in said outer member inner axial center bore with saidnonelastomeric inner member rotatable within said outer member, saidnonelastomeric inner member having an outer bonding cylindrical surfacesegment. The method includes providing an elastomeric surface effectdamper member mold for receiving said nonelastomeric inner member, saidmold including an outer surface groove relief distal from saidnonelastomeric inner member outer bonding cylindrical surface segment.The method includes providing an elastomer and molding said elastomer tosaid nonelastomeric inner member inside said mold to provide anelastomeric surface effect damper member bonded to said nonelastomericinner member outer bonding cylindrical surface segment, with saidelastomeric surface effect damper member having an outer groovedelastomer surface distal from said nonelastomeric inner member outerbonding cylindrical surface segment. The method includes rotationallyreceiving said nonelastomeric inner member in said outer member inneraxial center bore with said nonelastomeric inner member rotatable withinsaid outer member with said elastomeric surface effect damper outergrooved elastomer surface engaging said nonelastomeric outer memberfrictional interface inner surface segment and inhibiting an oscillatingrotation of said nonelastomeric inner member. The invention includesmaking a rotating oscillation damper by providing a nonelastomeric outertubular member having an inner axial center bore with a tubularcylindrical frictional interface inner surface segment, providing anonelastomeric inner member rotationally receivable in said outer memberinner axial center bore with said nonelastomeric inner member rotatablewithin said outer member, said nonelastomeric inner member having anouter bonding cylindrical surface segment, bonding an elastomericsurface effect damper member to said nonelastomeric inner member outerbonding surface segment with said elastomeric surface effect dampermember having an outer elastomer surface distal from said nonelastomericinner member outer bonding surface segment, receiving saidnonelastomeric inner member in said outer member inner axial center borewith said nonelastomeric inner member rotatable within said outer memberwith said elastomeric surface effect damper outer elastomer surfaceengaging said nonelastomeric outer member frictional interface innersurface segment and inhibiting an oscillating rotation of saidnonelastomeric inner member.

The invention includes an aircraft assembly, the assembly comprised of anonelastomeric outer member having an inner axial center bore with africtional interface smooth inner surface segment, a nonelastomericinner member having an outer bonding surface segment, the nonelastomericinner member rotationally received in the outer member inner axialcenter bore with the nonelastomeric inner member rotatable within theouter member, and an elastomeric shimmy damper member encompassing thenonelastomeric inner member outer bonding surface segment, theelastomeric shimmy damper member including an elastomer having an innerbonding surface segment and an outer grooved elastomer surface, theelastomeric damper inner bonding surface segment bonded to thenonelastomeric inner member outer bonding surface segment, and a grease,the grease disposed between the elastomeric damper outer groovedelastomer surface and the nonelastomeric outer member frictionalinterface inner surface segment with the elastomeric surface effectdamper outer grooved elastomer surface engaging the nonelastomeric outermember frictional interface inner surface segment and inhibiting anoscillating shimmy rotation of the nonelastomeric inner member.Preferably the damper includes grease dams for maintaining the greasebetween the frictional interface inner surface segment and the outergrooved elastomer surface, preferably with the grease dams inhibitingmigration of grease out of the frictional interface area.

The invention includes a method of making an assembly, the methodincluding providing a nonelastomeric outer member having an inner axialcenter bore with a frictional interface inner surface segment andproviding a nonelastomeric inner member rotationally receivable in theouter member inner axial center bore with the nonelastomeric innermember rotatable within the outer member, with the nonelastomeric innermember having an outer bonding surface segment. The method includesbonding an elastomer to the nonelastomeric inner member outer bondingsurface segment, the elastomer having an outer elastomer surface distalfrom the nonelastomeric inner member outer bonding surface segment. Themethod includes receiving the nonelastomeric inner member in the outermember inner axial center bore with the nonelastomeric inner memberrotatable within the outer member with the elastomer surface engagingthe nonelastomeric outer member frictional interface inner surfacesegment and inhibiting a shimmy rotation of the nonelastomeric innermember relative to the nonelastomeric outer member. Preferably thedamper includes a plurality of grease dams for inhibiting migration ofgrease out of the frictional interface area, preferably with the methodincluding providing the outer elastomer surface with a plurality ofgrooves terminating with grease dams.

The invention includes a method of making a shimmy damper, the methodincluding: providing a nonelastomeric outer tubular member having aninner axial center bore with a tubular cylindrical smooth frictionalinterface inner surface segment, providing a nonelastomeric inner memberrotationally receivable in the outer member inner axial center bore withthe nonelastomeric inner member rotatable within the outer member, thenonelastomeric inner member having an outer bonding cylindrical surfacesegment and an elastomer bonded to the nonelastomeric inner member outerbonding cylindrical surface segment. Preferably the elastomer has anouter elastomer surface distal from the nonelastomeric inner memberouter bonding cylindrical surface segment, the outer elastomer surfaceincluding a plurality of grooves and a plurality of grease dams. Themethod includes receiving the nonelastomeric inner member in the outermember inner axial center bore with the nonelastomeric inner memberrotatable within the outer member with the outer elastomer surfaceengaging the nonelastomeric outer member frictional interface innersurface segment and inhibiting an oscillating shimmy rotation of thenonelastomeric inner member.

The invention includes a shimmy damper for damping a rotatingoscillation, the shimmy damper comprised of a nonelastomeric outertubular member having an inner axial center bore with a tubularcylindrical frictional interface inner contiguous smooth surfacesegment. The damper includes a nonelastomeric inner member having anouter bonding cylindrical surface segment, the nonelastomeric innermember rotationally received in the outer member inner axial center borewith the nonelastomeric inner member rotatable within the outer member.The damper includes an elastomer encompassing the nonelastomeric innermember outer bonding surface segment, the elastomer having an innerbonding surface segment and an outer grooved elastomer surface, theelastomer inner bonding surface segment bonded to the nonelastomericinner member outer bonding surface segment. The damper includes agrease, the grease disposed between the outer grooved elastomer surfaceand the nonelastomeric outer member frictional interface inner surfacesegment with the outer grooved elastomer surface engaging thenonelastomeric outer member frictional interface inner surface segmentand inhibiting an oscillating shimmy rotation of the nonelastomericinner member. Preferably the outer grooved elastomer surface includes aplurality of grooves, preferably with grease dams. Preferably thegrooves include at least one groove type chosen from the groove typegroup comprised of helical segments grooves, axial grooves, andcircumferential grooves. Preferably the outer grooved elastomer surfaceincludes at least one mold axial flat, more preferably two mold flatswhich preferably provide mirror image surface halves. Preferably thedamper includes a grease inlet for injecting grease after insertion ofthe elastomer and the nonelastomeric inner member into the outer tubularmember.

The invention includes a method of making a damper, the methodcomprising: providing a nonelastomeric outer tubular member having aninner axial center bore with a tubular cylindrical frictional interfaceinner smooth surface segment, providing a nonelastomeric inner memberrotationally receivable in the outer member inner axial center bore withthe nonelastomeric inner member rotatable within the outer member, thenonelastomeric inner member having an outer bonding surface segment. Themethod includes providing an elastomer mold for receiving thenonelastomeric inner member, the mold including a mold flat and an outersurface groove relief distal from the nonelastomeric inner member outerbonding surface segment, providing an elastomer and molding theelastomer to the nonelastomeric inner member inside the mold to providean elastomer damper member bonded to the nonelastomeric inner memberouter bonding surface segment, with the elastomer damper member having amulti outer grooved elastomer surface distal from the nonelastomericinner member outer bonding surface segment. The method includesreceiving the nonelastomeric inner member in the outer member inneraxial center bore with the nonelastomeric inner member rotatable withinthe outer member with the damper outer multigrooved elastomer surfaceengaging the nonelastomeric outer member frictional interface innersurface segment and inhibiting a relative rotation of the nonelastomericinner member.

The invention includes a method of making a damper, the method includesproviding a nonelastomeric outer tubular member having an inner axialcenter bore with a tubular cylindrical frictional interface innersurface segment, providing a nonelastomeric inner member rotationallyreceivable in the outer member inner axial center bore with thenonelastomeric inner member rotatable within the outer member, thenonelastomeric inner member having an outer bonding cylindrical surfacesegment. The method includes bonding an elastomer damper member to thenonelastomeric inner member outer bonding surface segment with theelastomer damper member having an outer elastomer surface distal fromthe nonelastomeric inner member outer bonding surface segment, the outerelastomer surface including at least one grease dam. The method includesreceiving the nonelastomeric inner member in the outer member inneraxial center bore with the nonelastomeric inner member rotatable withinthe outer member with the elastomer damper outer elastomer surfaceengaging the nonelastomeric outer member frictional interface innersurface segment. The method includes providing grease, and disposing thegrease between the elastomer damper outer elastomer surface and thenonelastomeric outer member frictional interface inner surface segmentwith the grease dam containing the grease. Preferably the methodincludes injecting the grease through an inlet after receiving the innermember in the outer member. Preferably the method includes periodicallyinjecting grease during use of the damper.

The invention includes a rotation damper for damping a rotating motion.The damper is comprised of a nonelastomeric outer tubular member havingan inner axial center bore with a tubular cylindrical frictionalinterface inner contiguous smooth surface segment, a nonelastomericinner member having an outer bonding surface segment, the nonelastomericinner member received in the outer member inner axial center bore withthe nonelastomeric inner member within the outer member. The damperincludes an elastomer encompassing the nonelastomeric inner member outerbonding surface segment, the elastomer having an inner bonding surfacesegment and an outer grooved elastomer surface, the elastomer innerbonding surface segment bonded to the nonelastomeric inner member outerbonding surface segment and the outer grooved elastomer surfaceincluding a plurality of groove segments with grease dams. The damperincludes a grease, the grease disposed in the groove segments andbetween the outer grooved elastomer surface and the nonelastomeric outermember frictional interface inner surface segment with the outer groovedelastomer surface engaging the nonelastomeric outer member frictionalinterface inner surface segment and inhibiting a rotation of thenonelastomeric inner member with the grease dams inhibiting a migrationof the grease. Preferably outer grooved elastomer surface includes aplurality of helical groove segments, preferably all segments withgrease dams proximate the upper or the lower end. Preferably the groovesinclude at least one groove type chosen from helical segments grooves,axial grooves, and circumferential grooves. Preferably the elastomerincludes at least one mold axial flat, preferably two mold flats whichpreferably provide mirror image surface halves. Preferably the damperincludes a grease inlet for injecting grease after insertion of theinner member and elastomer into the outer member, preferably with agrease receiving reservoir groove proximate the grease inlet. Preferablyduring use of the damper periodically scheduled maintenance greaseinjections inject grease through grease inlet into the grease reservoir.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary of the invention, andare intended to provide an overview or framework for understanding thenature and character of the invention as it is claimed. The accompanyingdrawings are included to provide a further understanding of theinvention, and are incorporated in and constitute a part of thisspecification. The drawings illustrate various embodiments of theinvention, and together with the description serve to explain theprincipals and operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an aircraft landing gear assembly.

FIG. 2 shows an aircraft landing gear assembly with a cut away portion.

FIG. 3 shows a damper.

FIG. 4 shows an outer member damper component.

FIG. 5 shows an inner member damper component.

FIG. 6 shows an end view of the inner member damper component.

FIG. 7 shows an inner member damper component.

FIG. 8 shows molding an inner member damper component.

FIG. 9 shows a damper.

FIG. 10 shows a damper with a cut away portion.

FIGS. 11A-F show dampers and damper components.

FIGS. 12A-M show inner member damper components, cross sections anddetails of such.

FIG. 13 shows molding an inner member damper component.

FIG. 14 shows a damper cross section.

FIGS. 15A-B show an elastomer component.

FIGS. 16A-B show an elastomer component.

FIGS. 17A-B show an elastomer component.

FIGS. 18A-B show an elastomer component.

FIG. 19 shows an elastomer component.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Additional features and advantages of the invention will be set forth inthe detailed description which follows, and in part will be readilyapparent to those skilled in the art from that description or recognizedby practicing the invention as described herein, including the detaileddescription which follows, the claims, as well as the appended drawings.

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings.

The invention includes an aircraft vehicular front landing gear assembly10 for an aircraft 20. The landing gear assembly 10 is comprised of anonelastomeric outer upper strut shaft tubular member 12 having an inneraxial center bore 22 with a tubular cylindrical frictional interfaceinner surface segment 24. Preferably the nonelastomeric outer upperstrut shaft tubular member 12 is comprised of a metal tube. The landinggear assembly 10 is comprised of a nonelastomeric inner lower strutshaft tubular member 11 having an outer bonding cylindrical surfacesegment 26 with the nonelastomeric inner lower strut shaft memberrotationally received in the outer strut member inner axial center bore22 with the nonelastomeric inner strut member 11 rotatable within theouter strut member 12. Preferably the nonelastomeric inner strut member11 is comprised of a metal tube. The landing gear assembly 10 iscomprised of an elastomeric surface effect damper member 28 encompassingthe nonelastomeric inner strut member outer bonding cylindrical surfacesegment 26. The elastomeric surface effect damper member 28 has an innerbonding cylindrical surface segment 30 and an outer grooved elastomersurface 32. The elastomeric surface effect damper inner bonding surfacesegment 30 is bonded to the nonelastomeric inner strut member outerbonding surface segment 26. The landing gear assembly 10 includes asurface effect lubricant 34, the surface effect lubricant 34 disposedbetween the elastomeric surface effect damper outer grooved elastomersurface 32 and the nonelastomeric outer strut member frictionalinterface inner surface segment 24 with the elastomeric surface effectdamper outer grooved elastomer surface 32 engaging the nonelastomericouter strut member frictional interface inner surface segment 24 andinhibiting an oscillating shimmy rotation 36 of the nonelastomeric innerlower strut shaft member 11. Preferably the nonelastomeric inner lowerstrut shaft member 11 is grounded to a front nose wheel 17 with therotation of nonelastomeric inner lower strut shaft member 11 tied andfixed to the steering rotation of the wheel 17, with the front nosewheel 17 and the nonelastomeric inner lower strut shaft member 11rotationally actuated by a steering input 38, such as with steeringtubes 15, steering collar 14, torque link 13, lower strut 111 and thenonelastomeric outer upper strut shaft member 12 is rotationally fixedto an aircraft nose front 40 such as with upper strut 112.Nonelastomeric outer upper strut shaft member 12 is rotationally fixedin that it does not rotate with steering input 38 and/or the front nosewheel 17 that is being turned side to side to steer the aircraft, suchas during taxing and ground maneuvers by the aircraft 20. Nonelastomericouter upper member 12 is tied and fixed to the structure of the aircraftnose front 40 such as through rotationally fixed upper strut 112, withnonelastomeric inner lower member 11 rotating relative to outer uppermember 12. Preferably the elastomeric surface effect damper member outergrooved elastomer surface 32 has an upper end 42 and a distal lower end44 with an elastomer surface groove 46 traversing the elastomer surfacefrom the upper end 42 to the distal lower end 44, most preferably withgroove 46 traversing the elastomer surface from the upper end to thedistal lower end with the pattern of a helical spiral. Preferably theelastomeric surface effect damper member outer grooved elastomer surface32 includes a helical spiral elastomer surface groove 46. Preferably theelastomeric surface effect damper member outer grooved elastomer surface32 includes an elastomer surface groove 46.

The invention includes a method of making an aircraft vehicular frontlanding gear assembly 10. The method includes providing a nonelastomericmetal outer upper strut shaft tubular member 12 having an inner axialcenter bore 22 with a tubular cylindrical frictional interface innersurface segment 24. The method includes providing a nonelastomeric metalinner lower strut shaft tubular member 11 rotationally receivable in theouter strut member inner axial center bore 22 with the nonelastomericinner strut member 11 rotatable within the outer strut member 12, withthe nonelastomeric inner strut member 11 having an outer bondingcylindrical surface segment 26. The method includes bonding anelastomeric surface effect damper member 28 to the nonelastomeric innerstrut member outer bonding cylindrical surface segment 26, with theelastomeric surface effect damper member 28 having an outer groovedelastomer surface 32 distal from the nonelastomeric inner strut memberouter bonding surface segment 26. The method includes rotationallyreceiving the nonelastomeric inner lower strut shaft rotationallyreceivable member 11 in the outer strut member inner axial center bore22 with the nonelastomeric inner strut member 11 rotatable within theouter strut member 12 with the elastomeric surface effect damper outergrooved elastomer surface 32 engaging the nonelastomeric outer strutmember frictional interface inner surface segment 24 and inhibiting anoscillating shimmy rotation 36 of the nonelastomeric inner lower strutmember 11. Preferably the method includes molding the elastomericsurface effect damper member 28 onto the nonelastomeric inner strutmember outer bonding cylindrical surface segment 26. Preferably themethod includes providing an elastomeric surface effect damper membermold 60 for receiving the nonelastomeric inner strut member 11,providing an elastomer 56, and molding the elastomer 56 to thenonelastomeric inner strut member 11 inside the mold 60. Preferably theelastomer 56 is comprised of a natural rubber elastomer. In anembodiment the elastomer 56 is comprised of a silicone elastomer.Preferably the mold 60 includes an outer surface groove relief 62 distalfrom the nonelastomeric inner strut member outer bonding surface segment26, preferably the groove relief 62 traversing the elastomer mold cavitysurface to provide for a groove 46 traversing the elastomer surface fromthe upper end 42 to the distal lower end 44, preferably a helical spiralelastomer surface groove 46 from the upper end to the distal lower end.In an embodiment molding includes providing an elastomer transfer stock57, and transferring the elastomer transfer stock 57 under a pressureinto the mold 60, such as through a sprue with the mold comprising closefitting steel metal pieces clamped in place, and vulcanizing curing theelastomer 56 inside the mold 60 under a molding pressure, preferably amolding pressure of at least 1000 psi. Preferably providing thenonelastomeric outer upper strut shaft tubular member 12 includesproviding a nonelastomeric outer tubular member 12 with a tubularcylindrical frictional interface inner surface segment 24 having aninside diameter ID, and bonding an elastomeric surface effect dampermember to the nonelastomeric inner strut member outer bondingcylindrical surface segment includes bonding an elastomeric surfaceeffect damper member 28 to the nonelastomeric inner strut member outerbonding surface segment 26 to provide a bonded elastomeric surfaceeffect damper member 28 having an outer grooved elastomer surface 32with an outside diameter OD, with the elastomeric surface effect dampermember outer grooved elastomer surface outside diameter OD greater thanthe nonelastomeric outer upper strut tubular member frictional interfaceinner surface segment inside diameter ID. Preferably the inside diameterID of nonelastomeric outer tubular member 12 and the unreceived surfaceeffect damper outside diameter OD of surface effect damper member 28have a ratio ID/OD.gtoreq.0.75, preferably ID/OD.gtoreq.0.80, preferablyID/OD.gtoreq.0.85, preferably ID/OD.gtoreq.0.90, preferablyID/OD.gtoreq.0.92, most preferably ID/OD is in the range of 0.90 to0.99, preferably with the surface effect damper elastomer having acompression strain less than 10%, prefer less than 8%, preferably lessthan 7.75% when received inside said nonelastomeric outer tubular member12. Preferably the nonelastomeric outer tubular member 12 has a funnelend 23 with a progressively increasing inside diameter to facilitatereception of the nonelastomeric inner strut member 11 with surfaceeffect damper member 28 inside outer tubular member 12. Preferably afterreception of nonelastomeric inner strut member 11 with surface effectdamper member 28 inside outer tubular member 12 the relative axialmovement of nonelastomeric inner strut member 11 with surface effectdamper member 28 along inner axial bore 22 is minimal in that relativeaxial stroking is minimized. The method includes providing a frictionreducing lubricant 34 between the elastomeric surface effect damperouter grooved elastomer surface 32 and the nonelastomeric outer strutmember frictional interface inner surface segment 24. Preferably afriction reducing lubricant grease is disposed between the surfaces,preferably a grease containing a fluorocarbon. Preferably the frictionreducing lubricant 34 between the elastomeric surface effect damperouter grooved elastomer surface 32 and the nonelastomeric outer strutmember frictional interface inner surface segment 24 is comprised of asilicone lubricant.

The invention includes method of making a shimmy damper 100 for dampinga rotating oscillation 36. The method includes providing anonelastomeric outer upper tubular member 12 having an inner axialcenter bore 22 with a tubular cylindrical frictional interface innersurface segment 24. The method includes providing a nonelastomeric innerlower shaft member 11 rotationally receivable in the outer member inneraxial center bore 22 with the nonelastomeric inner member 11 rotatablewithin the outer member 12, with the nonelastomeric inner member 11having an outer bonding cylindrical surface segment 26. The methodincludes bonding an elastomeric surface effect damper member 28 to thenonelastomeric inner member outer bonding cylindrical surface segment26, with the elastomeric surface effect damper member 28 having an outergrooved elastomer surface 32 distal from the nonelastomeric inner memberouter bonding cylindrical surface segment 26. The method includesrotationally receiving the nonelastomeric inner member 11 in the outermember inner axial center bore 22 with the nonelastomeric inner member11 rotatable within the outer member 12 with the elastomeric surfaceeffect damper outer grooved elastomer surface 32 engaging thenonelastomeric outer member frictional interface inner surface segment24 and inhibiting an oscillating shimmy rotation 36 of thenonelastomeric inner member 11.

The invention includes a shimmy damper 100 for damping a rotatingoscillation 36. The shimmy damper 100 is comprised of a nonelastomericmetal outer upper tubular member 12 having an inner axial center bore 22with a tubular cylindrical frictional interface inner surface segment24. The shimmy damper 100 is comprised of a nonelastomeric metal innerlower member 11 having an outer bonding cylindrical surface segment 26,the nonelastomeric inner member 11 rotationally received in the outermember inner axial center bore 22 with the nonelastomeric inner member11 rotatable within the outer tubular member 12. The shimmy damper 100is comprised of an elastomeric surface effect damper member 28encompassing the nonelastomeric inner member outer bonding cylindricalsurface segment 26, with the elastomeric surface effect damper member 28having an inner bonding cylindrical surface segment 30 and an outergrooved elastomer surface 32. The elastomeric surface effect damperinner bonding cylindrical surface segment 30 is bonded to thenonelastomeric inner member outer bonding cylindrical surface segment26. The shimmy damper 100 is comprised of a surface effect lubricant 34disposed between the elastomeric surface effect damper outer groovedelastomer surface 32 and the nonelastomeric outer member frictionalinterface inner surface segment 24 with the elastomeric surface effectdamper outer grooved elastomer surface 32 engaging the nonelastomericouter member frictional interface inner surface segment 24 andinhibiting an oscillating shimmy rotation of the nonelastomeric innermember.

The invention includes a method of making a rotating oscillation damper100 for damping a rotating oscillation 36. The method includes providinga nonelastomeric metal outer tubular member 12 having an inner axialcenter bore 22 with a tubular cylindrical frictional interface innersurface segment 24 and providing a nonelastomeric metal inner member 11rotationally receivable in the outer member inner axial center bore 22with the nonelastomeric inner member 11 rotatable within the outermember 12. The nonelastomeric inner member 11 has an outer bondingcylindrical surface segment 26, and the method includes providing anelastomeric surface effect damper member mold 60 for receiving thenonelastomeric inner member 11, with the mold including an outer surfacegroove relief 62 distal from the nonelastomeric inner member outerbonding cylindrical surface segment 26, preferably with the grooverelief traversing the elastomer surface mold cavity from an upper end 42to a distal lower end 44. Preferably the outer surface groove relief 62has a helical spiral pattern for producing an elastomer surface groove46. The method includes providing an elastomer 56 and molding theelastomer to the nonelastomeric metal inner member 11 inside the mold 60to provide a an elastomeric surface effect damper member 28 bonded tothe nonelastomeric inner member outer bonding cylindrical surfacesegment 26, with the elastomeric surface effect damper member 28 havingan outer grooved elastomer surface 32 distal from the nonelastomericinner member outer bonding cylindrical surface segment. The methodincludes receiving the nonelastomeric inner member 11 in the outermember inner axial center bore 22 with the nonelastomeric inner member11 rotatable within the outer member 12 with the elastomeric surfaceeffect damper outer grooved elastomer surface 32 engaging thenonelastomeric outer member frictional interface inner surface segment24 and inhibiting an oscillating rotation 36 of the nonelastomeric innermember 11.

The invention includes an aircraft landing gear shimmy damper assembly10 such as shown in FIG. 1-11. The assembly includes a nonelastomericouter member 12 having an inner axial center bore 22 with a frictionalinterface smooth cylindrical inner surface segment 24. The aircraftassembly includes a nonelastomeric inner member 11 having an outerbonding surface segment 26. The nonelastomeric inner member 11 isrotationally received in the outer member inner axial center bore 22with the nonelastomeric inner member 11 rotatable within the outermember 12. The assembly includes an elastomeric surface effect shimmydamper member encompassing the nonelastomeric inner member outer bondingsurface segment 26, the elastomeric surface effect shimmy damper memberincluding an elastomer having an inner bonding surface segment 30 and anouter grooved elastomer surface 32, the elastomeric damper inner bondingsurface segment 30 is bonded to the nonelastomeric inner member outerbonding surface segment 26. The aircraft assembly includes a surfaceeffect lubricant solid state nonliquid gel grease 34, the grease 34disposed between the elastomeric damper outer grooved elastomer surface32 and the nonelastomeric outer member frictional interface innersurface segment 24 with the elastomeric surface effect damper outergrooved elastomer surface 32 engaging the nonelastomeric outer memberfrictional interface inner surface segment 24 and inhibiting anoscillating shimmy rotation 36 of the nonelastomeric inner member 11relative to the outer member 12 while preferably maintaining the grease34 between the frictional interface smooth cylindrical inner surfacesegment 24 and the outer grooved elastomer surface 32. Preferably thefriction reducing lubricant grease 34 between the elastomeric surfaceeffect damper outer grooved elastomer surface 32 and the nonelastomericouter strut member frictional interface inner surface segment 24 is asolid state nonliquid gel grease containing a fluorocarbon. Preferablythe fluorocarbon gel grease is comprised of viscous grease thickenedwith PTFE. Preferably the grease 34 is comprised of a siliconelubricant, preferably a fluorocarbon gel silicone grease, preferably agrease including a PTFE and a dimethyl silicone. As shown in FIG. 11,preferably the outer grooved elastomer surface 32 surface retains greaseproximate the frictional interface smooth cylindrical inner surfacesegment 24 with a plurality of grease dams 48 which inhibit themigration of grease 34 out of the frictional interface area of the outerelastomer surface 32 and the receiving interface smooth cylindricalsurface segment 24. Preferably the outer grooved elastomer surface 32includes a plurality of grease dams 48. The grease dams 48 arepreferably formed with the outer elastomer surface 32 and control theflow of grease 34 to inhibit the migration of grease out through theupper and lower ends 42, 44 between the elastomer surface 32 and thefrictional surface 24.

Preferably the outer grooved elastomer surface 32 includes a pluralityof grease dams 48. As shown in FIG. 12, preferably the grooved elastomersurface 32 includes a plurality of grooves 46 terminating with greasedams 48, preferably with the grooved 46 comprised of helical groovesegments that terminate at their ends proximate the upper and lower ends42, 44 with grease dams 48 to control the flow of grease from exitingthe groove at the upper and lower ends 42, 44. Preferably the pluralityof surface grooves 46 end with grease dams 48. Preferably the surfacegrooves 46 are comprised of elastomer surface groove depression pathsthat end with a rising elastomer surface forming the grease dam 48.Preferably the grease dam is a raised elastomer radially extendingoutward and away from the inner bonding surface 30 and the inner member11 to impede the flow of grease out of the groove 46.

Preferably the assembly outer grooved elastomer surface 32 has a firstupper end 42 and a second distal lower end 44 with a plurality ofgrooves 46 between the first upper end 42 and the second distal lowerend 44, preferably with grease dams 48 at the ends of the grooves 46,preferably with grease dams 48 proximate the upper end 42 and the distallower end 44. Preferably the plurality of grooves 46 includes more thanone helical groove 46. Preferably the plurality of grooves 46 arecomprised of a plurality helical segments, preferably with the helicalsegments not completely circling the inner member 11. Preferably thehelical grooves do not traverse all way from upper end 42 to lower end44. Preferably the plurality of grooves 46 include at least one axialgroove 46′. Preferably the plurality of grooves 46 include at least onecircumferential groove 46″. Preferably the elastomeric surface effectdamper member outer grooved elastomer surface 32 has the upper end 42and the distal lower end 44 with at least one axial mold flat 52traversing the elastomer surface 32 from the upper end 42 to the distallower end 44, preferably with the axial flat 52 including at least oneaxial groove 46′. Preferably the axial mold flat 52 traverses theelastomer surface from the first upper end 42 to the distal second lowerend 44, preferably with the axial flat 52 including at least one flataxial surface groove 46′ traversing the elastomer surface from the firstupper end 42 to the second distal lower end 44. Preferably the multigrooved elastomer surface includes two axial mold flats 52 traversingthe elastomer surface from the first upper end 42 to the second distallower end 44 along the longitudinal center axis 16, preferably with thetwo axial mold flats 52 oppositely oriented, preferably about 180degrees apart. Preferably grease dams 48 at the intersection of theaxial flat 52 and the non-axial grooves (circumferential grooves andhelical grooves) maintain grease 34 in the non-axial grooves. Preferablythe two axial mold flats 52 include an axial flat raised plateau 54,preferably with the axial mold flat including the axial flat raisedplateau 54 with a flat axial surface groove 46′ on each side, with theaxial mold flats 52 molded in the elastomer surface with the axial flatraised plateau surface area 54 surrounded by the axial groovedepressions 46′. Preferably the outer grooved elastomer surface 32includes at least one axial mold flat 52, preferably with a first andsecond axially running mold flats 52 separating the surface 32 into twohalves, preferably two mirror image helical groove segment area halveswith non-parallel helical groove orientations with opposite helicaltwists that would intersect if not for the axial flats 52 such as shownin FIG. 12E. Preferably, the helical groove segments have a helicalgroove pitch angle relative to the longitudinal axis 16 that ispreferably less than eighty five degrees, preferably no greater thanseventy nine degrees, preferably no greater than seventy one degrees,and most preferably about sixty degrees (60.±0.10 degrees) such as shownin FIG. 12. Preferably the outer grooved elastomer surface 32 includes aplurality of elastomer surface grooves 46, 46′ which terminate withraised elastomer dam grease obstructions 48 which radially extendoutward and away from the inner bonding surface 30. Preferably theassembly includes a grease inlet for injecting grease 34 between theelastomer surface 32 and the frictional interface surface 24 after thenonelastomeric inner member 11 is received in the outer member inneraxial center bore 22. As shown in FIG. 14, preferably grease inlet 50 isproximate and oriented with a circumferential surface groove 46″.Preferably the assembly includes at least one grease dam 48 forretaining the grease 34. Preferably the grooved elastomer surface 32includes a plurality of grooves and the grease dams, preferably with thegrooves ending with grease dams. Preferably the elastomer surface groovedepression paths end with a rising elastomer surface, preferably araised elastomer radially extending outward and away from the innermember 11 to provide a grease dam 48 to control the flow of grease 34out of the groove depression.

The invention includes a method of making an aircraft landing gearassembly. The method includes: providing a nonelastomeric outer member12 having an inner axial center bore 22 with a frictional interfaceinner surface segment 24, and providing a nonelastomeric inner member 11rotationally receivable in the outer member inner axial center bore 22with the nonelastomeric inner member 11 rotatable within the outermember 12. Preferably the nonelastomeric inner member 11 has an outerbonding surface segment 26. The method includes bonding an elastomericsurface effect damper member elastomer 28 to the nonelastomeric innermember outer bonding surface segment 26, the elastomer 28 having anouter elastomer surface 32 distal from the nonelastomeric inner memberouter bonding surface segment 26. The method includes receiving thenonelastomeric inner member 11 in the outer member inner axial centerbore 22 with the nonelastomeric inner member 11 rotatable within theouter member 12 with the elastomer surface 32 engaging thenonelastomeric outer member frictional interface inner surface segment24 and inhibiting an oscillating shimmy rotation of the nonelastomericinner member 11 relative to the nonelastomeric outer member 12,preferably with the elastomer surface 32 including a plurality ofgrooves 46 with grease dams 48. Preferably the method includes moldingthe elastomer 28 onto the nonelastomeric inner member outer bondingsurface segment 26 with the outer elastomer surface 32, preferably moldbonding the elastomer to the inner member 11 in an elastomer mold 60while molding the outer elastomer surface 32 with the plurality ofgrooves 46 with grease dams 48. Preferably such as shown in FIG. 13,molding the elastomer 28 with the outer elastomer surface 32 includemolding with at least one mold flat 52, preferably with two mold flats52, most preferably with a two piece mold 60 with a first and secondmold insert 61, preferably molding with no more than three mold inserts61, most preferably only with two mold inserts 61 parted at the moldflats 52. Preferably the method includes providing the elastomer outerelastomer surface 32 with a plurality of grooves 46. Preferably theplurality of grooves 46 include more than one helical groove, preferablya plurality helical segments with the helical grooves not completelycircling the inner member 11, preferably with the helical grooves nottraversing all the way from the upper end 42 to lower end 44. Preferablythe plurality of grooves 46 include at least one axial groove 46′.Preferably the plurality of grooves 46 include at least onecircumferential groove 46″. Preferably the method including providing asolid state nonliquid grease 34 and a plurality of grease dams 48 forcontrolling the flow of the grease 34 along the outer elastomer surface32. Preferably the method includes providing a solid state nonliquidgrease inlet 50, preferably through the outer member 12, and a solidstate nonliquid grease 34, and injecting the grease 34 between the outerelastomer surface 32 and the frictional interface inner surface segment24, preferably by injecting the grease through the grease inlet 50 afterthe inner member 11 is inserted into the outer member 12 with the outerelastomer surface 32 and frictional interface 24 engaging. Preferablythe grease 34 is injected through the inlet 50 to a preferablycircumferential grease receiving reservoir groove 46″ after the innermember 11 is inserted into the outer member 12 with the outer elastomersurface 32 and frictional interface 24 engaged, with the grease dams 48controlling the exiting of grease 34. Preferably providing thenonelastomeric outer member 12 includes providing a nonelastomeric outermember with a frictional interface inner surface segment 24 having aninside diameter ID, and bonding an elastomer 28 to the nonelastomericinner member outer bonding surface segment 26 includes bonding anelastomeric surface effect damper member elastomer 28 to thenonelastomeric inner member outer bonding surface segment 26 to providean elastomeric surface effect outer elastomer surface 32 with anelastomer groove projection outside diameter POD and an elastomer groovedepression outside diameter DOD, with the outer elastomer surfaceoutside diameter POD greater than the nonelastomeric outer memberfrictional interface inner surface segment inside diameter ID, and theDOD<ID with the bottom of grooves 46 less than ID of the outer member12. Preferably the POD is comprised of the elastomer surface effectribbed surface producing the resistive force to the relative rotation.Preferably the raised plateau 54 has an elastomer thickness X, theelastomer groove projection has an elastomer thickness Y, and the greasedam 48 has an elastomer thickness Z, preferably with Y>X and Y>Z.Preferably the provided elastomeric surface effect damper memberelastomer 28 has an outer elastomer surface 32 with a plurality ofgrooves. Preferably the outer grooved elastomer surface 32 has a firstupper end 42 and a second distal lower end 44 with a plurality ofgrooves 46 between the first upper end 42 and the second distal lowerend 44, preferably with grease dams 48 at the ends of the grooves 46,preferably with grease dams 48 proximate the upper end 42 and the distallower end 44. Preferably the plurality of grooves 46 includes more thanone helical groove 46. Preferably the plurality of grooves 46 arecomprised of a plurality helical segments, preferably with the helicalsegments not completely circling the inner member 11. Preferably thehelical grooves do not traverse all the way from upper end 42 to lowerend 44. Preferably the plurality of grooves 46 include at least oneaxial groove 46′. Preferably the plurality of grooves 46 include atleast one circumferential groove 46″. Preferably the elastomeric surfaceeffect damper member outer grooved elastomer surface 32 has the upperend 42 and the distal lower end 44 with at least one axial mold flat 52traversing the elastomer surface 32 from the upper end 42 to the distallower end 44, preferably with the axial flat 52 including at least oneaxial groove 46′. Preferably the multi grooved elastomer surfaceincludes two axial mold flats 52 traversing the elastomer surface fromthe first upper end 42 to the second distal lower end 44 along thelongitudinal center axis 16, preferably with the two axial mold flats 52oppositely oriented, preferably about 180 degrees apart. FIG. 15 showsan elastomeric surface effect damper member elastomer 28 with an outerelastomer surface 32 with a plurality of grooves includingcircumferential grooves 46″ and helical segment grooves 46. FIG. 16shows an elastomeric surface effect damper member elastomer 28 with anouter elastomer surface 32 with a plurality of grooves including acentral middle grease receiving circumferential groove 46″ and helicalsegment grooves 46. FIG. 17 shows an elastomeric surface effect dampermember elastomer 28 with an outer elastomer surface 32 with a pluralityof grooves including a helical segment grooves 46 and two opposinglyoriented axial mold flats 52. FIG. 18 shows an elastomeric surfaceeffect damper member elastomer 28 with an outer elastomer surface 32with a plurality of grooves including axial grooves 46″ and a centralmiddle grease receiving circumferential groove 46″. FIG. 19 shows anelastomeric surface effect damper member elastomer 28 with an outerelastomer surface 32 with a plurality of grooves including axial grooves46″ and a central middle grease receiving circumferential groove 46″.Preferably the assembly provides for grease lubrication of the damperdevice after initial assembly and preferably at maintenance intervals.The damper device provides for entrapment of the lubricant grease 34 inthe torsion damper device. The entrapment function is utilized for theassembly of the damper and maintenance grease filling with the greasedams 48 preventing the grease from migrating out of the frictionalinterface contact region of the damper. In a preferred embodiment theelastomer groove projection contact shape includes a rounded shape. FIG.15 and 16 show the grease dams 48 with the grooves. FIG. 15 shows threecircumferential grooves and FIG. 16 only shows one. Preferably thecentral middle grease receiving circumferential groove 46″ is orientedproximate a grease inlet 50. FIG. 14 shows an embodiment with thelubrication fittings grease inlet 50 installed on the outer member 12with the bonded elastomer 28 inner member 11 inserted into the outermember 12. FIG. 17 shows an embodiment with axial mold flats. FIG. 18shows an embodiment with axial grooves with dams and the central middlegrease receiving circumferential lubrication groove 46″. FIG. 19 showsan embodiment elastomer groove projection contact rounded shape that canbe applied to both helical patterned and axial patterned grooves. Thegroove projection contact portion of the damper is completed roundrather than a flatter arc portion that follows the arc length of theouter diameter. Preferably the assembly provides for lubricating thedamper after assembly, retaining the grease in the elastomer grooves,and an axial groove structure that is parallel to the longitudinalcenter axis 16. FIGS. 15 and 16 show a circumferential groove 46″ forreceiving and transporting the grease from the entry point grease inlet50 to the individual grooves and out along their respective lengths. Thedams 48 at the end of the grooves retain the grease in the groove.

The invention includes the method of making the shimmy damper. Themethod includes providing the nonelastomeric outer tubular member 12having an inner axial center bore 22 with a tubular cylindricalfrictional interface inner surface segment 24. The method includesproviding a nonelastomeric inner member 11 rotationally receivable inthe outer member inner axial center bore with the nonelastomeric innermember 11 rotatable within the outer member 12. Preferably thenonelastomeric inner member 11 has an outer bonding cylindrical surfacesegment 26 and elastomer 28 bonded to the nonelastomeric inner memberouter bonding cylindrical surface segment 26. Preferably the elastomer28 has an outer elastomer surface 32 distal from the nonelastomericinner member 11, the outer elastomer surface 32 including a plurality ofgrooves 46, 46′, 46″ and a plurality of grease dams 48. The methodincludes receiving the nonelastomeric inner member in the outer memberinner axial center bore with the nonelastomeric inner member rotatablewithin the outer member with the elastomer surface 32 engaging thenonelastomeric outer member frictional interface inner surface segment24 and inhibiting an oscillating shimmy rotation of the nonelastomericinner member 11 relative to the outer member 12. Preferably theelastomer 28 is molded to the nonelastomeric inner member 11 with theouter elastomer surface 32 having two axial mold flats 52. Preferablythe method includes providing a grease inlet 50 for injecting grease 34after the nonelastomeric inner member 11 is received in the outer memberinner axial center bore 22, and wherein the elastomer surface 32includes a grease receiving groove, preferably a grease reservoirgroove, with the grease inlet proximate the elastomer surface greasereceiving groove, preferably circumferential groove 46″ is proximategrease inlet 50, where grease 34 is injected after the elastomer surface32 is contacting the tubular cylindrical frictional interface innersurface segment 24, preferably with the circumferential groove 46″intersecting non-circumferential grooves that have some axial componentsuch as 46 and 46′. Preferably the outer elastomer surface 32 includes aplurality of helical grooves 46 terminating with grease dams 48,preferably with grease dams 48 at the upper and lower ends 42, 44 ofsurface 32, preferably with two axial mold flats 52 parting between twomirror image halves that have the helical groove patterns.

The invention includes shimmy damper 100 for damping a rotatingoscillation. The shimmy damper includes of a nonelastomeric outertubular member 12 having an inner axial center bore 22 with a tubularcylindrical frictional interface inner contiguous smooth surface segment24, and a nonelastomeric inner member 11 having an outer bondingcylindrical surface segment 26, the nonelastomeric inner member 11rotationally received in the outer member inner axial center bore 22with the nonelastomeric inner member rotatable within the outer member.The damper includes an elastomer 28 between the inner and outer members,preferably encompassing the nonelastomeric inner member outer bondingsurface segment, the elastomer 28 preferably having an inner bondingsurface segment 30 and an outer grooved elastomer surface 32, theelastomer inner bonding surface segment 30 bonded to the nonelastomericinner member outer bonding surface segment. The damper preferablyincludes a grease 34, the grease 34 disposed between the outer groovedelastomer surface 32 and the nonelastomeric outer member frictionalinterface inner surface segment 24 with the outer grooved elastomersurface 32 engaging the nonelastomeric outer member frictional interfaceinner surface segment 24 and inhibiting an oscillating shimmy rotationof the nonelastomeric inner member. Preferably the elastomer includes aplurality of grooves, preferably with grease dams 48, preferably withthe grooves including at least one groove type chosen from helicalsegments grooves 46, axial grooves 46′, and circumferential grooves 46″.Preferably the elastomer 28 includes at least one mold axial flat 52,preferably two mold flats 52, which preferably provide mirror imagesurface halves. Preferably the damper includes a grease inlet 50 forinjecting grease 34 after insertion of the inner member 11 in the outermember 12.

The invention includes a method of making a rotating oscillation damper100. The method includes providing a nonelastomeric outer tubular member12 having an inner axial center bore 22 with a tubular cylindricalfrictional interface inner smooth surface segment 24. The methodincludes providing a nonelastomeric inner member 11 rotationallyreceivable in the outer member inner axial center bore 22 with thenonelastomeric inner member 11 rotatable within the outer member 12.Preferably the nonelastomeric inner member 11 having an outer bondingsurface segment 26, and providing an elastomer mold 60 for receiving thenonelastomeric inner member 11, the mold 60 including a mold flat 52 andan outer surface groove relief 62 distal from the nonelastomeric innermember outer bonding surface segment 26, and providing an elastomer 57and molding the elastomer to the nonelastomeric inner member 11 insidethe mold 60 to provide an elastomer damper member bonded to thenonelastomeric inner member outer bonding surface segment, with theelastomer damper member having a multi-outer grooved elastomer surface32 distal from the nonelastomeric inner member outer bonding surfacesegment. The invention includes receiving the nonelastomeric innermember 11 in the outer member inner axial center bore 22 with thenonelastomeric inner member rotatable within the outer member with thedamper outer multigrooved elastomer surface 32 engaging thenonelastomeric outer member frictional interface inner surface segment24 and inhibiting a relative rotation of the nonelastomeric inner member11 relative to the outer member 12.

The invention includes a method of making a rotating oscillation damper100, the method includes providing a nonelastomeric outer tubular member12 having an inner axial center bore 22 with a tubular cylindricalfrictional interface inner surface segment 24. The method includesproviding a nonelastomeric inner member 11 rotationally receivable inthe outer member inner axial center bore 22 with the nonelastomericinner member 11 rotatable within the outer member 12, the nonelastomericinner member having an outer bonding cylindrical surface segment 26. Themethod includes bonding an elastomer damper member 28 to thenonelastomeric inner member 11 with the elastomer 28 having an outerelastomer surface 32 distal from the nonelastomeric inner member, theouter elastomer surface 32 including at least one grease dam 48. Themethod includes receiving the nonelastomeric inner member 11 in theouter member inner axial center bore 22 with the nonelastomeric innermember rotatable within the outer member with the elastomer damper outerelastomer surface 32 engaging the nonelastomeric outer member frictionalinterface inner surface segment 24. The method includes providing agrease 34, disposing the grease 34 between the elastomer damper outerelastomer surface 32 and the nonelastomeric outer member frictionalinterface inner surface segment 24, preferably with the grease dams 48containing the grease 34. Preferably the grease 34 is injected throughan inlet 50 after receiving the inner member 11 in the outer member 12,preferably with periodic injection of grease 34 during use of thedamper. The elastomer 28 inhibits an oscillating rotation of thenonelastomeric inner member 11 relative to the outer member 12.

The invention includes a rotation damper 100 for damping a rotatingmotion. The damper includes a nonelastomeric outer tubular member 12 anda nonelastomeric inner member 11. The damper includes a tubularcylindrical frictional interface contiguous smooth surface segment 24and a bonding cylindrical surface segment 26. The nonelastomeric innermember 11 is rotationally received in the outer member 12 with thenonelastomeric inner member 11 rotatable within the outer member 12. Thedamper includes an elastomer 28 encompassing the nonelastomeric innermember 11, with the elastomer 28 between the inner member 11 and theouter member 12 with the elastomer 28 bonded to bonding cylindricalsurface segment 26, with the elastomer 28 having a grooved elastomersurface 32 contacting and engaging the tubular cylindrical frictionalinterface contiguous smooth surface segment 24. The grooved elastomersurface 32 includes a plurality of grooves with grease dams 48. Thedamper includes a grease 34, the grease 34 disposed in the grooves andbetween the grooved elastomer surface 32 and the nonelastomeric memberfrictional interface surface segment 24 with the grooved elastomersurface 32 engaging the nonelastomeric member frictional interfacesurface segment and inhibiting a rotation of the nonelastomeric innermember relative to the outer member with the grease dams 48 inhibiting amigration of the grease 34. Preferably the grooved elastomer surface 32includes a plurality of helical groove segments 46, preferably withgrease dams 48 proximate the upper or the lower ends. Preferably thegrooved elastomer surface 32 includes at least one groove type chosenfrom helical segments grooves 46, axial grooves 46′, and circumferentialgrooves 46″. Preferably the elastomer 28 includes at least one moldaxial flat 52, preferably two mold flats 52, which preferably providemirror image surface halves. Preferably the damper includes a greaseinlet 50 for injecting grease 34 after insertion of inner member 11 intoouter member 12, preferably with a grease receiving reservoir,preferably a circumferential groove 46″. Preferably during use of thedamper, periodically scheduled maintenance grease injections areinjected through grease inlet 50 into grease reservoir groove 46″.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the present inventionwithout departing from the spirit and scope of the invention. Thus, itis intended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. An aircraft landing gear assembly, said landing gear assemblycomprised of a nonelastomeric outer aircraft landing gear vertical strutmember having an inner axial center bore with a frictional interfaceinner surface segment, a nonelastomeric inner aircraft landing gearvertical strut member having an outer bonding surface segment, saidnonelastomeric inner aircraft landing gear vertical strut memberrotationally received in said outer aircraft landing gear vertical strutmember inner axial center bore with said nonelastomeric inner aircraftlanding gear vertical strut member rotatable within said outer aircraftlanding gear vertical strut member, and an elastomeric surface effectdamper member encompassing said nonelastomeric inner aircraft landinggear vertical strut member outer bonding surface segment, saidelastomeric surface effect damper member having an inner bonding surfacesegment and an outer grooved elastomer surface, said elastomeric surfaceeffect damper inner bonding surface segment bonded to saidnonelastomeric inner aircraft landing gear vertical strut member outerbonding surface segment, and a surface effect lubricant, said surfaceeffect lubricant disposed between said elastomeric surface effect damperouter grooved elastomer surface and said nonelastomeric outer aircraftlanding gear vertical strut member frictional interface inner surfacesegment with said elastomeric surface effect damper outer groovedelastomer surface engaging said nonelastomeric outer aircraft landinggear vertical strut member frictional interface inner surface segmentand inhibiting an oscillating shimmy rotation of said nonelastomericinner aircraft landing gear vertical strut member.
 2. An aircraftlanding gear assembly as claimed in claim 1, wherein said nonelastomericinner aircraft landing gear vertical strut member is grounded to a frontnose wheel with said front nose wheel and said nonelastomeric inneraircraft landing gear vertical strut member rotationally actuated by asteering input and said nonelastomeric outer aircraft landing gearvertical strut member rotationally fixed to an aircraft nose front. 3.An aircraft assembly, said assembly comprised of a nonelastomeric outermember having an inner axial center bore with a frictional interfaceinner surface segment, a nonelastomeric inner member having an outerbonding surface segment, said nonelastomeric inner member rotationallyreceived in said outer member inner axial center bore with saidnonelastomeric inner member rotatable within said outer member, and anelastomeric shimmy damper member encompassing said nonelastomeric innermember outer bonding surface segment, said elastomeric shimmy dampermember including an elastomer having an inner bonding surface segmentand an outer elastomer surface, said elastomeric damper inner bondingsurface segment bonded to said nonelastomeric inner member outer bondingsurface segment, and a grease, said grease disposed between saidelastomeric damper outer elastomer surface and said nonelastomeric outermember frictional interface inner surface segment with said elastomericsurface effect damper outer elastomer surface engaging saidnonelastomeric outer member frictional interface inner surface segmentand inhibiting an oscillating shimmy rotation of said nonelastomericinner member.
 4. An aircraft assembly as claimed in claim 3, whereinsaid outer elastomer surface includes a plurality of grease dams.
 5. Anaircraft landing gear assembly as claimed in claim 3, wherein saidelastomer surface includes a plurality of elastomer surface grooveswhich terminate with raised elastomer grease obstructions which radiallyextend outward and away from the inner bonding surface.
 6. An aircraftassembly as claimed in claim 3, wherein said assembly includes a greaseinlet for injecting grease after said nonelastomeric inner member isreceived in said outer member inner axial center bore.
 7. An aircraftassembly as claimed in claim 3, wherein said assembly includes at leastone grease dam for retaining said grease.
 8. A method of making anassembly, said method comprising: providing a nonelastomeric outermember having an inner axial center bore with a frictional interfaceinner surface segment, providing a nonelastomeric inner memberrotationally receivable in said outer member inner axial center borewith said nonelastomeric inner member rotatable within said outermember, said nonelastomeric inner member having an outer bonding surfacesegment, bonding an elastomer having an outer elastomer surface distalfrom said nonelastomeric inner member outer bonding surface segment,receiving said nonelastomeric inner member in said outer member inneraxial center bore with said nonelastomeric inner member rotatable withinsaid outer member with said elastomer surface engaging saidnonelastomeric outer member frictional interface inner surface segmentand inhibiting a shimmy rotation of said nonelastomeric inner memberrelative to said nonelastomeric outer member.
 9. A method as claimed inclaim 8, said method including molding said elastomer onto saidnonelastomeric inner member outer bonding surface segment with saidouter elastomer surface.
 10. A method as claimed in claim 8, said methodincluding providing a grease and a plurality of grease dams forcontrolling the flow of said grease along said outer elastomer surface.11. A method as claimed in claim 8, said method including providing agrease inlet and a grease, and injecting said grease between said outerelastomer surface and said frictional interface inner surface segment.12. A method of making a shimmy damper, said method comprising:providing a nonelastomeric outer tubular member having an inner axialcenter bore with a tubular cylindrical frictional interface innersurface segment, providing a nonelastomeric inner member rotationallyreceivable in said outer member inner axial center bore with saidnonelastomeric inner member rotatable within said outer member, saidnonelastomeric inner member having an outer bonding cylindrical surfacesegment and an elastomer bonded to said nonelastomeric inner memberouter bonding cylindrical surface segment, said elastomer having anouter elastomer surface distal from said nonelastomeric inner memberouter bonding cylindrical surface segment, said outer elastomer surfaceincluding a plurality of grooves and a plurality of grease dams,receiving said nonelastomeric inner member in said outer member inneraxial center bore with said nonelastomeric inner member rotatable withinsaid outer member with said elastomer surface engaging saidnonelastomeric outer member frictional interface inner surface segmentand inhibiting an oscillating shimmy rotation of said nonelastomericinner member.
 13. A method as claimed in claim 12, wherein saidelastomer is molded to said nonelastomeric inner member with the outerelastomer surface having two mold flats.
 14. A method as claimed inclaim 12, said method including providing a grease inlet for injectinggrease after said nonelastomeric inner member is received in said outermember inner axial center bore, and wherein said elastomer surfaceincludes a grease receiving groove, with said grease inlet proximatesaid elastomer surface grease receiving groove.
 15. A method as claimedin claim 12, wherein said outer elastomer surface includes a grease dam.16. A shimmy damper for damping a rotating oscillation, said shimmydamper comprised of a nonelastomeric outer tubular member having aninner axial center bore with a tubular cylindrical frictional interfaceinner surface segment, a nonelastomeric inner member having an outerbonding surface segment, said nonelastomeric inner member rotationallyreceived in said outer member inner axial center bore with saidnonelastomeric inner member rotatable within said outer member, and anelastomer encompassing said nonelastomeric inner member outer bondingsurface segment, said elastomer having an inner bonding surface segmentand an outer elastomer surface, said elastomer inner bonding surfacesegment bonded to said nonelastomeric inner member outer bonding surfacesegment, and a grease, said grease disposed between said outer elastomersurface and said nonelastomeric outer member frictional interface innersurface segment with said outer elastomer surface engaging saidnonelastomeric outer member frictional interface inner surface segmentand inhibiting an oscillating shimmy rotation of said nonelastomericinner member.
 17. A method of making a damper, said method comprising:providing a nonelastomeric outer tubular member having an inner axialcenter bore with a tubular cylindrical frictional interface innersurface segment, providing a nonelastomeric inner member rotationallyreceivable in said outer member inner axial center bore with saidnonelastomeric inner member rotatable within said outer member, saidnonelastomeric inner member having an outer bonding cylindrical surfacesegment, bonding an elastomer damper member to said nonelastomeric innermember outer bonding surface segment with said elastomer damper memberhaving an outer elastomer surface distal from said nonelastomeric innermember outer bonding surface segment, said outer elastomer surfaceincluding at least one grease dam, receiving said nonelastomeric innermember in said outer member inner axial center bore with saidnonelastomeric inner member rotatable within said outer member with saidelastomer damper outer elastomer surface engaging said nonelastomericouter member frictional interface inner surface segment, providing agrease, disposing said grease between said elastomer damper outerelastomer surface and said nonelastomeric outer member frictionalinterface inner surface segment.
 18. A damper for damping a motion, saiddamper comprised of a nonelastomeric outer tubular member having aninner axial center bore with a tubular cylindrical frictional interfaceinner contiguous smooth surface segment, a nonelastomeric inner memberhaving an outer bonding surface segment, said nonelastomeric innermember received in said outer member inner axial center bore with saidnonelastomeric inner member within said outer member, and an elastomerencompassing said nonelastomeric inner member outer bonding surfacesegment, said elastomer having an inner bonding surface segment and anouter elastomer surface, said elastomer inner bonding surface segmentbonded to said nonelastomeric inner member outer bonding surface segmentand said outer elastomer surface including a plurality of groovesegments with grease dams, and a grease, said grease disposed in saidgroove segments and between said outer elastomer surface and saidnonelastomeric outer member frictional interface inner surface segmentwith said outer elastomer surface engaging said nonelastomeric outermember frictional interface inner surface segment and inhibiting arotation of said nonelastomeric inner member with said grease damsinhibiting a migration of said grease.
 19. A method of making a damper,said method comprising: providing a nonelastomeric outer tubular memberhaving an inner axial center bore, providing a nonelastomeric innermember rotationally receivable in said outer member inner axial centerbore with said nonelastomeric inner member rotatable within said outermember, bonding an elastomer damper member to a nonelastomeric memberbonding cylindrical surface segment with said elastomer damper memberhaving an elastomer surface distal from said nonelastomeric memberbonding surface segment, said elastomer surface including at least onegrease dam, receiving said nonelastomeric inner member in said outermember inner axial center bore with said nonelastomeric inner memberrotatable within said outer member with said elastomer damper elastomersurface engaging a nonelastomeric member frictional interface surfacesegment, providing a grease, disposing said grease between saidelastomer damper elastomer surface and said nonelastomeric memberfrictional interface surface segment with said grease dam containingsaid grease, with said elastomer damper elastomer surface engagementwith said nonelastomeric member frictional interface surface segmentinhibiting an oscillating rotation of said nonelastomeric inner memberrelative to said nonelastomeric outer member.
 20. A damper for damping amotion, said damper comprised of a nonelastomeric outer tubular memberhaving an inner axial center bore, a nonelastomeric inner member, saidnonelastomeric inner member rotationally received in said outer memberinner axial center bore with said nonelastomeric inner member rotatablewithin said outer member, a nonelastomeric member bonding cylindricalsurface segment and a nonelastomeric member frictional interface surfacesegment, and an elastomer encompassing said nonelastomeric inner member,said elastomer having a bonding surface segment and a elastomer surface,said elastomer bonding surface segment bonded to said nonelastomericmember bonding surface segment and said elastomer surface including aplurality of groove segments with grease dams, and a grease, said greasedisposed in said groove segments and between said elastomer surface andsaid nonelastomeric member frictional interface surface segment withsaid elastomer surface engaging said nonelastomeric member frictionalinterface surface segment and inhibiting a rotation of saidnonelastomeric inner member relative to said outer member with saidgrease dams inhibiting a migration of said grease.